In general, this application relates to procedures and processes for the most efficient changeovers between different product families.
An electronics assembly line is an integrated system of process equipment, pick-and-place equipment, board handling units, inspection machines, and software which allows communication between all the pieces. A pick-and-place equipment has a function of mounting electronics components onto printed circuit boards. Each electronics product has a number of common parts but may also require distinct parts. In modern electronics, the products have a number of common parts across product lines, but each style and type of product will also have distinct parts. In-modern electronics, the product shave a number of common parts across product lie but each style and type of product will also have distinct parts.
One type of automated assembly line equipment is surface mount technology or SMT equipment. Such equipment is equipped with a set number of feeder tables which in turn hold component feeders. Each feeder supplies a distinct type of part to a robotic mounter.
When a new setup is introduced to a production line different sets of feeders must be assembled and loaded onto the tables to supply different types and quantity of components.
The Assignee of the present application utilizes a software tool to optimize the changeover process once the programs, priorities and constraints are fed in advance. A good deal of work has gone into making the changeover between products more efficient. As an example, for years the Assignee of the present application has utilized a computer program to optimize the feeder tables and feeders which are switched between any two product families being manufactured. Many factors are taken into consideration by the optimization program, including an attempt to minimize the numbers of tables and feeders which must be changed. The optimizer is capable of identifying the required changes in feeders and feeder tables with the least frequencies to build numerous product families.
In designing a changeover, the computer program will attempt to minimize the number of feeder tables that will need to be changed by making as many of the feeder tables as possible uniform across product families. The program may attempt to identify tables which could be made uniform by having common parts for any number of different product families included in common feeder tables.
However, the software tool by itself is not sufficient to achieve the quickest changeovers due to the human factor. Thus, the prior art has attempted to make the process of changing over the assembly of two components as systematic as possible. However, certain deficiencies still exist. Production staff assigned to perform these changes on the SMT lines must be trained on the most efficient process. Moreover, the process engineer is unable to predict the approximate time for each changeover. To date, no equipment vendor or production consultant has developed a training tool tying the shortest possible changeover time with the most efficient changeover procedures. Particularly in an industry where every manufacturer is suffering from shortages of qualified workers and high turnover rate, it is critical to develop such a tool to improve business performance. However, to date, no way of predicting the necessary time for a change, nor in tying that time to the steps that should be taken at any one time has been provided.
In disclosed features of this invention, a method of performing quick changeovers on assembly lines between the manufacture of various product families incorporates a number of training steps. An instructional visual tool is created for the workers who will be performing the changeovers describing the steps each worker should be taking in sequence.
The set of instruction should be reviewed by every production staff assigned to the line from line supervisor to changeover technicians prior to any changeover to implement the process correctly. This can be viewed by all of the workers prior to beginning the changeover, and can also be reviewed by supervisory personnel during the changeover to ensure the changeover is proceeding in the right order. Moreover, this visual tool is preferably provided with a timeline that will provide feedback of whether the steps are taking place at the proper time and in the proper order.
In other features of this invention, a method is provided to predict changeover time. The method identifies the required changes in feeders and feeder tables based upon matrixes of the common and unique parts for the planned productions. The procedure also creates a matrix of loading-feeder time for each product family. Once the Charts are created, it is possible for Process Engineer to calculate approximate time for each changeover. This approximate time can also be utilized in the visual tool described above in order to more accurately create the timeline.
In yet another feature, each changeover technician is provided with a badge indicating the changeover steps, for example, which feeder table to be changed how and when. Though the badge can be unique to each changeover, it could also include common or generic steps. instructions, and a chart for identifying the approximate time necessary for a particular changeover are all disclosed. Further, this invention extends to the combination and sub-combinations of each of these individual components.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.